Natural Resources keeps its eye on climate trends
Climate change could pose a large threat to Nova Scotia’s forests, but it’s not just because of increasing temperatures.
The forest industry and researchers say that while fire is what most people think of when it comes to climate change’s impact on the province’s forest, there are other issues as well.
Aldona Wiacek, an assistant professor at Saint Mary’s University’s department of environmental science, said there has been an increase in forest fires across the country as a whole.
She said the consensus is emerging that the increasing frequency of forest fires is climate-related.
Much of the research she has read is based on the boreal forests of Central and Western Canada. While Nova Scotia has a mostly Acadian forest, “the effects are going to be the same. . . . This is causing a drying of plants, so what happens is that the fuel for fires is becoming drier and better,” Wiacek said. “As plants are dying a lot more (of that) material becomes available, which is also more fuel for the fire.”
Natural Resources Canada says on its website that climate change during this century is expected to result in more frequent fires in many boreal forests, and conditions are predicted to be such that the area burned by the end of the century could be double what it has been in recent decades.
It also says that the impacts of climate change, such as insect outbreaks, ice storms and high winds, could create more damaged or dead wood in forests and increase the risk of fires.
“There is growing consensus that as wildland fire activity increases, fire agency suppression efforts will be increasingly strained,” the site said.
Wiacek said that while climate change can also result in more storms and extreme precipitation, they aren’t expected to be enough, or frequent enough, to suppress fires “because it doesn’t take a long time to really dry out a forest. One week of heat is all you need to prime the forest for burning.”
She also said more storms brings more lightning — which could also cause more fires — and more winds, which can increase the severity of the fires.
John Ross, the director of forest protection for the province’s Department of Natural Resources, said there isn’t enough historical information to show any trends that fires here are becoming bigger or more intense.
“We just don’t have enough data to definitively say that,” he said.
There were some bigger fires in the southwestern part of the province in 2016 during a drought in that area.
“There’s no conclusive evidence to say that that was a result of climate change, but there may be an effect there,” Ross said. “We don’t know for sure.”
He said fire crews in western Canada are concerned about climate change, and have had some significant fire problems over the past few years.
“There are a lot of people in the science community who think that is because of climate change and drier weather,” he said.
In Nova Scotia, the number of fires over the past 20 years has for the most part ranged between 170 and 300, and the average losses per fire have been low. Only four times in that period have more than 1,000 hectares burned in a year.
“We do have years where it was worse and we have more fires and bigger fires, and we have years where it’s less. It’s hard to say there’s any trend there right now,” he said. “One thing we do notice is that there are more fires happening in early spring and later in the fall.”
With what the West is seeing in terms of bigger and more intense fires, Ross said Nova Scotia officials are concerned about the future.
“We have to keep an eye on it,” Ross said. “It’s certainly a different climate out West, and we have the effect of the ocean here. I don’t think it would be as pronounced as the western part of the country, but it’s certainly a thing to keep an eye on.”
Jeff Bishop, the executive director of Forest Nova Scotia, said climate change “is definitely something that’s on watch from folks in our industry.”
But, he said, the unknowns make things difficult for those who work in forestry.
“You look at predictions of where things are going to go, but we’re a bit unique. If we say we’re going to see these changes in 20, 50 or 100 years, that’s the scale we’re planning on. When you’re planting trees today, you’re looking at what those impacts can be over the lifecycle of what you’re planning today.”
He said people are looking at whether they should be planting or encouraging particular trees to grow, and what they’ll see over the 100-year lifetime of the tree.
“We can’t wait two years and say ‘oh, we didn’t do that right.’ It’s difficult to shift. That’s the biggest concern: it’s not something you can shift on a dime to react to something . . . on something that takes so long to grow to maturity.”
He said increased winds, dry weather and insect infestations exacerbated by climate change all worry the industry.
“If you look at the last 10 to 15 years, it wasn’t necessarily significant in the level of hurricanes, but we’re getting more major wind events, and it looks like it’s becoming more of a trend,” he said. “That’s part of what the global climate change folks are saying: winds will increase.”
He said higher temperatures mean dryer conditions, and some species of trees work better in wetter habitat.
Drier weather could also stunt the growth of trees, lead to dry conditions for forest fires.
And warmer temperatures mean less winter kill of pests.
“Those winters where you’d have four, six, or eight weeks of nice, cold snaps of -20C or colder, we don’t get those like we used to, so that means the pests are not only not dying, they’re not slowing down, they’re still breeding on more cycles,” he said.
“(The impact of climate change) just compounds from a number of areas . . . on what we’re trying to do.”
He said he noticed an increase in loss from wind events over the past few years, “but is that a longterm trend? It’s too early to tell, but if you talk to some guys who have been around for a long time, I would say they’re seeing it more and more.”
He said possible ways to deal with climate change, including planting different species and changing management practices “are still in the fairly early research stage. ... It takes multiple generations of science sometimes watching these things and looking at what the effects are.”
He said trying different varieties of trees here might not work if the conditions aren’t hot enough or dry enough, and native insects here “could absolutely devastate something it hasn’t seen before.”